Sander



May 15 1951 R. E. VENDIENy 2,553,432

SANDER Fil'ed Aug. 3o, 194s 21 34 B VENToR.'

1N 2 RAGNOR EVENDIEN.

BY ggI-ZORNEYS.

iifatented May l5, 195i SANDER Ragnor E. Vendien, Marquette, Mich., assignor to Maxwell K. Reynolds, Marquette, Mich.

Application August 30, 1949, Serial No. 113,156

3 Claims. l

This invention relates generally to the art of sanding and is particularly -concerned with a new 'sander which is particularly suited for use in small diameter openings.

One type of sander made heretofore consisted of an abrasive tube, a rubber core within the tube land means for compressing the core axially and expanding it radially into supporting and driving engagement with the tube. The tube was composed of sandpaper, emery cloth or the like and' was usually made in long lengths so that sections of the desired length could be cut olf when re- "quired. Another type of prior sander consisted f a wheel having a radial slit in its periphery and a l ratchet controlled pin rotatably mounted between -the hub and rim. An abrasive tape was wrapped varound the rim and its ends were passed through the radial slit and secured to the pin. Rotation ofthe pin tensioned the tape on the wheel. The ratchet and pin require a certain amount of space and consequently this device was made only in large diameter sizes.

Neither of the foregoing types of Sanders has vbeen entirely satisfactory and neither was suitvmade small enough to operate in openings having diameters as small as about one-half inch.

v This invention embodies the use of two tubular members, one within the other, having opposed Ntruste-conical surfaces with means for relatively and simultaneously moving the parts rotationally and longitudinally, the frusto-conical surfaces vgripping the ends of the tape surrounding the outer body and tensioning it.

In the drawings accompanying and forming a part of this specification,

' Fig. 1 is a side elevational view of one form of v sander embodying the present invention;

Fig. 2 is a central, sectional view taken on line 2-2 of Fis. l;

Fig. 3 is a cross-sectional View taken on line 3-3 of Fig. 1*; and

Fig. 4 is a View similar to Fig. 2 showing a modified form of the invention.

The sander of Figs. 1 to 3 comprises a tubular metal shell A and a tubular metal body B. The shell A includes a tubular wall I having a cylindrical outer surface around which an abrasive tape 2 may be Wound, a frusto-conical inner surface 3, a slit 4 which extends longitudinally thereof but stops short of the open end of the shell, an end wall 5 which closes one end of the shell and a stem projecting from the end Wall 5 and having an interiorly threaded axial opening l. This stern 6 may be used for attachment to any suitable form of apparatus employed to rotate the sander.

The tubular body B comprises a tubular wall I0 having a truste-conical outer surface II cor-'- responding to the frusto-conical inner surface 3 of the shellA, an end wall I2 at the smaller end of Wall I0 and a .threaded stem I3 projecting from end wall I2 to enter the opening 'l in stem G and engage with the threads therein. At its outer end body B is provided with a transverse pin le to serve as a convenient means for turning that body when it is in the tubular shell.

It will be understood that in assembling the above described device an abrasive tape 2 is wrapped around the outer cylindrical surface of shell I and the ends are passed through the longitudinal slit 4 and are extended circumferen- -tially in the same direction along the inner frusto-conical surface 3 of the shell. In this position the smooth backs of the tape ends will bear against the conical surfaces of the shell and body While the abrasive faces of these ends are opposed to each other. Then the tubular body B is moved endwise into the shell I and the threads on stem I3 are engaged with the threads in opening l. In their loosely assembled positions the shell and body are concentric but spaced apart, i. e., there is a radially short annular space between the frusto-conical surfaces 3 and II of the shell and body respectively. As the shell and body are rotated relatively, the interengagying threads move these two members relatively land decrease the radial length of that annular space with resultant pressing of the two frustoconical surfaces against the ends of the tape therebetween. As this simultaneous rotational and longitudinal relative movement of the two members continues, the pressure exerted by the frusto-conical surfaces on the tape ends increases until the tape ends are firmly held in xeol position. During this time the members are creating progressively increasing friction between the frusto-conical surfaces and the tape ends and this friction tends to draw the tape ends farther into the interior of the outer shell with consequent tensioning and tightening of the strip around the cylindrical shell. A

Thus the application of relative rotational movement t0 the shell and body results in simultaneous relative rotational and longitudinal movement of these parts With consequent tensioning and securing of the tape on the outer member.

The embodiment of the present invention shown in Fig. 4 comprises a tubular shell A and a tubular body B. The shell A' comprises a tubular wall 2| having a cylindrical outer surface around which an abrasive tape 2 kmay be wound, a frusto-conical inner surface 23, a slit 24 which extends longitudinally of the shell but stops short of the ends thereof, and an end wall 25 which closes one end of the shell and has an inwardly extending projection 26 with an interiorly threaded axial opening 21. The threads 28 at the inner end of opening' 21 are provided for a purpose presently to appear while threads 29 at the outer end are provided.v to engage with a threaded device for rotating the sander.

The tubular body B comprises a wall 30 hav- -i-n'g a frusto-conical outer surface 3| corresponding to the truste-conical inner surface 23 of the shell A', a transverse wall 32 'and a stem 33 projecting therefrom toward the smaller end of the body and providedwith threads 34 to engage with threads 28 of shell A'.

It will be understood that the operation of the device of Fig. 4 is substantially the same as that described above with reference to Figs. l to 3 inclusive and hence such operation need not be fully described. Briefly stated, the operation is as follows: A length of abrasive tape somewhat longer than the circumferential length of shell A isv wrapped around that shell and the ends are passed through slit 24. Both ends are positioned close to each other and to the inner surface 23 of the shell. The body B is inserted vinto shell A and threads A34 are screwed into threads 28 with eventual locking of the tape ends between surfaces '23 and 3lY and tensioning of the tape about shell A'.

Hai/"ingv thus described the present invention so that others skilled in the art may be able to understand and practice the invention, I state that what I desire tosecure by Letters Patent is dened in what is claimed, it being. understood that I intend tol include within what'is claimed all non-patentable variations and changes of the illustrated embodiment of the invention.

What is claimed is:

1. A sander comprising a tubular shell having a' cylindrical outer surface around which an abrasive tape may be' wound, 'a frusta-conical inner surface and a longitudinally extending slit through which the ends of the tape may project into the interior of the shell, and a tubular body extending telescopically into said shell and having an outer frusta-conical surface Corresponding to the inner surface of said shell and defining therewith an annular space to receive the ends of said tape, and means including interengaging threads operatively associated with said shell and said bodyb for simultaneously and relatively rotating them and moving them axially and pressing the tape ends therebetween.

2. A sander comprising a tubular shell having a cylindrical outer surface around which an abrasive tape may be wound, a frusto-conical inner surface and a longitudinally extending slit through which the ends of said tape may project into the interior of the shell, an end wall closing one end of said shell and a stem projecting from said end 'wall and having a threaded axial opening, and a tubular body having an outer f'rusto-conical surface corresponding to the inner surface of said shell and defining therewith a radially short annular space of suicient size to receive the ends of said tape, an end wall at'the smal-ler end of said' body, a threaded stem projecting axially from the said end wall' `and engaging with the threads of said threaded opening, and means for rotating said body to adjust the relative axial positions of said body and shell, said body serving, when its threaded stem is screwed into said threadedopening, to press the ends of said tape between saidf-rusto-conical surfaces and to draw the ends of the tape into the shell and tighten the strip on thel outside; of the shell and to hold the tape in position onthe shell.

3. A sander comprising a tubular shell having a cylindrical outer surface, a truste-conical inner surface and a longitudinally extending slit through said shell, and an end wall closing one end of said shell and having an inward axial projection, said wall and project-ion having a threaded aixal opening, and a tubular body having an outer frusto-conical surface corresponding to the inner `surface of said shell vand defining therewith a radially short annular space, and a cross wall within the body having a threaded projection engaging the adjacent threads of said threadedV opening. A l

RAGNR REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 170,178 Locke Nov. 23, 1875 392,608 I-Iin'man Nov. 13, 1888 734,581 Lockwood July 28, 1903 1,326,336 Bendix etal Dec. 30, 1919 '1,374,052 Brassner et al Apr. 5, 1921 

